1. Technical Field
The present invention relates to a magnetic read/write head, and in particular, to a planar silicon head with a structure protected from an overcurrent/overvoltage and a method for fabricating the same.
2. Related Art
Magnetic heads are used for reading and writing magnetically coded data stored on a magnetic storage medium such as a magnetic disk. An inductive magnetic head generally includes two conductive layers, called poles, separated by an insulating layer. Conductive wires are embedded within the insulating layer between the poles. The insulating layer is typically narrowest near the tips of the poles. The portion of the insulating layer near the pole tips is called the front gap, and the thickness of the insulating layer between the pole tips is called the gap length. Typically, the substrate on which the layers have been deposited is formed into a slider defining one of more air bearing surfaces. Examples of inductive magnetic head are disclosed in U.S. Pat. No. 4,727,643 for Method For Manufacturing A Magnetic Head By A Thin-Film Technique issued to Schewe et al., U.S. Pat. No. 5,333,086 for Thin Film Two-Pole Inductive Magnetic Head With Minimized Secondary Pulses issued to Frey et al., and U.S. Pat. No. 5,452,166 for Thin Film Magnetic Recording Head For Minimizing Undershoots And A Method For Manufacturing The Same issued to Aylwin et al.
A planar structure magnetic head has lower inductance than inductive magnetic heads. As a result, planar structure magnetic heads are widely substituted for inductive magnetic heads. There are a number of different planar structure magnetic heads and fabrication processes as disclosed, for example, in U.S. Pat. No. 4,949,207 for Planar Structure Thin Film Magnetic Head issued to Lazzari, U.S. Pat. No. 5,282,308 for Thin Film Planarization Process For Fabricating Magnetic Heads Employing A Stitched Pole Structure issued to Chen et al., U.S. Pat. No. 5,283,942 for Sacrificial Layer Planarization Process For Fabricating A Narrow Thin Film Inductive Head issued to Chen et al., and U.S. Pat. No. 5,434,733 for Planar Head Having Separate Read And Write Gaps issued to Hesterman et al. Typically, the planar silicon head is formed by a drilling process for drilling holes in a silicon substrate to form an electrode, an electroplating process for forming pole pieces, a gap forming process for forming a gap positioned in the upper pole piece, and a bump forming process for forming bumps positioned at the rear of the head. However, I have observed that internal connector for most planar silicon heads is not uniformly plated due to surface contamination. As such, each time an overvoltage/overcurrent is applied through the head connector, the connector is corroded by metallic stress and contamination. If the current continues to flow, the corrosion becomes severe, and the internal connector is disconnected. As a result, the planar silicon head loses its intended function. Accordingly, an improved planar silicon head for reading and writing magnetically coded data stored on a magnetic storage medium is still desired.